/**
 * Copyright (c) 2020 QingLang, Inc. <baisui@qlangtech.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package com.qlangtech.tis.db.parser;

import java.util.ArrayList;

/**
 * @author 百岁（baisui@qlangtech.com）
 * @date 2020/04/13
 */
public class TokenBuffer {

    private int currentPosition;

    private final ArrayList<Token> tokenList;

    private final int tokenSize;

    public TokenBuffer(ArrayList<Token> tokenList) {
        this.tokenList = tokenList;
        this.tokenSize = tokenList.size();
    }

    public Token nextToken() {
        if (currentPosition >= tokenSize) {
            return null;
        }
        return this.tokenList.get(currentPosition);
    }

    public Token popToken() {
        if (currentPosition >= tokenSize) {
            return null;
        }
        return this.tokenList.get(currentPosition++);
    }

    public void resetCurrentPosition(int savePosition) {
        this.currentPosition = savePosition;
    }

    public int getCurrentPosition() {
        return this.currentPosition;
    }
}
